The present invention relates to multi-path flow cell correction.
Multi-path flow cell systems are known in the art. They are also known as so-called absorbance detectors or flow-through cells such as are commonly used, for example, in high performance liquid chromatography (HPLC). A performance criterion of an absorbance detector is its dynamic range. Mainly two problems are the limiting factors: signal noise and stray light. While noise performance is determined by the light throughput through the sample (or also called analyte), stray light (or more general: false light) is determined by the necessary optics and its components.
Increasing the dynamic range by using multi-path flow cell systems is known in the art. U.S. Pat. No. 6,342,948 B1 (Gilby), for example, discloses a flow cell for absorbance detection with at least two different optical path lengths. A method and accompanying apparatus for automatically extending the linear dynamic absorbance range of absorbance detectors including multi-light path flow cells is disclosed, for example, by U.S. Pat. No. 5,214,593 (Magnussen). The articles “Dynamic Range Improvement in Fourier Transform Infrared Spectrometry”, Thomas Hirschfeld, Analytical Chemistry, Volume 50 No. 8, page 1225-1226, July 1978, and the article “Multi-path Cells for Extending Dynamic Range of Optical Absorbance Measurements”, Purnendu K. Dasgupta, Analytical Chemistry, Volume 56, page 1401-1403, 1984 disclose the theoretical background of absorbance sensors with more than one flow cell of different path lengths.